<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="https://cdn.staticfile.org/jquery/3.2.1/jquery.min.js"></script>
</head>

<body>
    <div class="box">
        <ul>
            <li>这是li01</li>
            <li>这是li02</li>
            <li>这是li03</li>
            <li>这是li04</li>
            <li>这是li05</li>
        </ul>
    </div>
    <ul>
        <li>lili01</li>
        <li>lili02</li>
        <li>lili03</li>
        <li>lili04</li>
        <li>lili05</li>
    </ul>


    <script>


        /*   console.log(jQuery);// 函数对象
          console.log($); */


        /*  var num = 10;
         num.toFixed(); */


        console.log($('header'));
        console.log($('header,.box'));
        console.log($('.box li'));

        console.log($('.box li:first'));// 找到第一个li
        console.log($('.box li').first());

        console.log($('.box li:last'));// 找到第eq(n)中索引值n为n的li标签

        console.log($('.box li').last());

        console.log($('.box li:lt(2)')); // 获取雄安与参数索引值的标签 找到的是0  1
        console.log($('.box li'));

        console.log($('.box li:gt(2)'));// 获取大于参数索引值的标签 找的是 3 4 

        console.log($('.box li'));
        console.log($('.box li:eq(2)'));




    </script>
</body>

</html>